Grinding mill



J. H. JOHNS GRINDING MILL Nov. 3, 1936.

Filed 061;. 25, 1935 2 Sheets-Sheet l JZYYEHTOR: JAMES H. JOHNS.

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GRINDING MILL Filed 001;. 23, 1935 2 Sheets-Sheet 2 INVENIR.'

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JAMES .JOHNS BY' M Patented Nov. 3, 1936 UNITED STATES PATENT oFFicE GRnvDING MILL James H. Johns, Los Angeles, Calif.

Application October 23, 1935, Serial No. 46,401.

2 Claims.

This invention relates to improvements in grinding mills.

The principal object of the invention is to produce a device which will grind material and classify it simultaneously, thus eliminating the necessity of separate classifying equipment.

. Another object is to separate the iines from the oversize or coarse particles in the material being lfed to the grinder.

A further object is to provide means for the quick removal of the material as soon as ground to desired fineness, thus reducing overgrinding to a minimum, and producing a product of more nearly uniform size than is now possible in present grinding practice.

A still further object is to produce a device which is of simple construction, one which is economical to manufacture, one which will require va minimum amount of power, and one A.which will have high efciency.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. l is a vertical cross section of my device, showing portions thereof in elevation,

Fig. 2 is a fragmentary cross sectional view on the line 2-2 of Fig. 3,

Fig. 3 is a top plan view of the grinder element and a portion of the base thereof,

Fig. 4 is a fragmentary cross sectional view showing the employment of tapered rollers (or o rods) as the grinding medium, and

Fig. 5 is a cross sectional View on the line 5-5 of Fig. 3.

There are many trades in which it is necessary to grind materials in order to free certain chemicals, minerals, ores, and the like, and it is a grinder for such a purpose that I have devised.

In the accompanying drawings wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 5 designates a base having a plurality of standards 6, which support a bearing 1, directly above a bearing 8, in the base 5. Positioned in these bearings is a hollow shaft 9, to which is secured a casting or shell II, which has a gear I2, capable of engaging a gear I3, mounted upon a shaft I4, Through this gear arrangement, the casting II may be rotated on bearing 32 in the base 5. Secured within the casting are wear plates I6, 33 and 34. Wear plates I6 have a serrated surface, the purpose of which will be later seen.

Connected at the top of shaft 9 is a suitable swivel joint connection 43, for connection to the water feed line for utilizing hollow shaft 9 as a water passage I'I, which communicates with a plurality of radial bores I8. Radial bores are connected by a plurality of circular bores 35, and from which bores, vertical bores I9 extend to the surface of the Wear plates I6. Suspendedy above, from bolts 4I, which are held by nuts 42 to the standards 6 through the medium of chains 2l, is a weighted element 22 also having wear plates 23, 36 and 31 secured thereto. The wear plates 23 are provided with serrated surfaces. Openings 24 extend through the Wear plates 23 angularly upward through the weightedl element 22. A feed opening 26 extends from the top of the weighted element angularly downward so as to permit material to enter the space between the wear plates I6 and 23. Wear-plates 38 are secured to hollow shaft 9.

`In the form of the device shown in Figs. 1, 2 and 5, I have shown the space between the wear plates occupied by grinding balls of various sizes, which are represented by the circles 2l. In the modified form shown in Fig. 4, the grinding action is accomplished by the use of varying sized tapered rollers 28, the other parts remaining the same except that the grinding surfaces of the wear plates under and over the rollers have ilat inclined rather than serrated surfaces. Mounted on top of the stationary element are spiral guides 29. A trough (or launder) 3l surrounds the upper edge of the device and is secured by brackets 40 to standards 6 and is adapted to receive and discharge therefrom as will be presently described.

Assuming that the parts are arranged as shown in Fig. 1, but with the stationary element raised until clear of the grinding balls, by means of a chain block or other means to release the starting strain and the casting is filled with water and rotated. By this procedure, the power required to start the device is reduced to a minimum. The stationary element 22 is then lowered until its weight rests on the balls. By means of the stationary element, sufficient pressure is applied on the grinding balls to cause them to rotate against the wear plates of the casting II, of the stationary element 22 and against each other as the casting rotates. Material is dropped on the stationary element so that the same discharges into the opening 26 and passes downwardly into engagement with the grinding balls directly therebelow. Due to the rotation of the casting II the balls have a forward movement as they rotate and carry the material with them between the grinding surfaces, becoming thoroughly mixed with it. The rotation and movement of the balls, the weight of the balls themselves, and the pressure of the stationary element on them, cause a very decided grinding and crushing action to take place, which action is suiiicient to grind up material fed into the device. Due to the serrated Wear plates, greater grinding surface and increased grinding action is obtained. Water is introduced through the bore l1 inshaft. 6, and eventually reaches the bores I9 and is discharged upwardly into the grinding mass. As the material is ground up, the ner particles are carried upwardly by the rising current of water through the openings 24 and the space around vthe weighted element 22; and4 due to centrifugal action they are discharged over the lip'39 at top of casting Il into the trough 3|, from which point they are carried to suitable concentrato-rs. Should any of the coarser material not ground sufficiently fine be carried upwardly, it will come to rest upon the top of the weighted element and due to the circular current-of water caused by the rotation of casting Il and shaftg, it will gradually be carried byvtheaction of the spiral guides back to the opening 26. As the balls become worn and are gradually ground up, additional ones of uniform or varying sizes as the operation designates may be-inserted through the opening 26 along with the material being fed. Removal of the balls, replacementk and inspection of wear plates etc., may be made through a suitable manhole in the side of the rotor.

In the modified form new rollers may be inserted through a suitable manhole in the side of the rotor similar to the one using balls. yThe worn rollers stay in the device until'ground up,

thus giving a grinding mass of varying sized rollers, the same as the balls. It will thus be ap parent that with my device a veryv decided grinding and classifying process takes place', the material staying in the device until'j it 4 has been ground to the ineness desired, this being accomplished and governed by the amount of water introduced into the device.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:-

1. In a device of the character described, a base `varotary element mounted on said base, a stationaryelement loosely suspended in said rotating'elem'ent, serrated wear plates carried by each of said elements, grinding means interposed between said wear plates, an inclined feed passage extending through said stationary element and inclined downwardly in the direction of rotation of said rotating element, discharge means extending upwardly through saidstationary element, spiral guides positioned on said stationary element, said guides being-capable of conducting coarse material to said downwardly inclined feedpassage.

2. In a device of the character described, a. base, a rotary element mounted on said base, a stationary element loosely suspended in said rotating element, serrated wear plates carried by each of said elements, grinding means interposed between said wear plates, an inclined feed passage extending through said stationary element and inclined downwardly in the direction of rotation of said rotating element, discharge means extending upwardly through vsaid stationary element, spiral guides positioned on said stationary element, said guides being capable of conducting coarse material to said downwardly inclined feed passage, and means for elevating said stationary member, said flexible suspending means also permitting a partial rotation of said stationar element.

JAMES H. JOHNS. 

